Earhart was last heard from on July 2, 1937, as she tried to become the first woman pilot to circumnavigate the globe. Earhart was declared dead two years later after the U.S. concluded she had crashed somewhere in the Pacific Ocean. Her remains were never found.

Investigators said they have found evidence Earhart and Noonan were blown off course, but survived a crash landing in a Marshall Islands.

The photograph was discovered in a long-forgotten file in the National Archives.

The photo, labeled "Jaluit Atoll" is believed by experts to have been taken in 1937, shows an Anglo woman with short-hair, dressed in slacks, sitting on a dock with her back to the camera. A man, pictured standing near her, looks like Earhart’s navigator, Fred Noonan.

Multiple theories about what happened Earhart and Noonan have been presented over the years, but none with as much visual backup as the newly found photograph.

Independent analysts told the History Channel that the photo appears legitimate and undoctored.

Shawn Henry, former executive assistant director for the FBI and an NBC News analyst, has studied the photo and feels confident it shows the famed pilot and her navigator.

The woman’s build and hairstyle were compared to other photographs of Earhart, and the similarity is unmistakable. The man believed to be Noonan is facing the camera, so his face could be carefully analyzed by experts.

"The hairline is the most distinctive characteristic," said Ken Gibson, a facial recognition expert who studied the image. "It's a very sharp receding hairline. The nose is very prominent."

"When you pull out, and when you see the analysis that's been done, I think it leaves no doubt to the viewers that that's Amelia Earhart and Fred Noonan," Henry told NBC News.

The investigative team behind the History Channel special believes the photo may have been taken by someone spying on Japanese military activity in the Pacific for the U.S.

Les Kinney, a retired government investigator who has spent 15 years looking for Earhart clues, told NBC that the photo "clearly indicates that Earhart was captured by the Japanese."

Costello reported that people who live in the Marshall Islands have claimed they saw Earhart's plane crash before she and Noonan were taken away. Native schoolchildren insisted they saw Earhart in captivity. The story was even documented in postage stamps issued in the 1980s.

Japanese authorities told NBC News they have no record of Earhart being in their custody.

"We believe that the Koshu [a Japanese ship] took her to Saipan [in the Mariana Islands], and that she died there under the custody of the Japanese," Gary Tarpinian, the executive producer of the History Channel special, said.

"We don't know how she died," Tarpinian said. "We don't know when."

It is not clear if the U.S. government knew who was in the photo. If it was taken by a spy, the U.S. may not have wanted to compromise that person by revealing the image, Costello said.

Costello said the History Channel special will also introduce other evidence during the special to back the theory that Earhart and Noonan survived a crash landing and died in the custody of the Japanese.